How can strings be concatenated in PHP to avoid fatal errors?

When concatenating strings in PHP, it is important to ensure that all variables being concatenated are properly initialized. If any variable is null or undefined, it can cause a fatal error. To avoid this, you can use the null coalescing operator (??) to provide a default value in case a variable is null.

// Example of concatenating strings with null coalescing operator to avoid fatal errors
$name = "John";
$age = null;

echo "Name: " . $name . ", Age: " . ($age ?? "Unknown");